Recovery and conversion of shale oil mist

ABSTRACT

SHALE OIL MIST IS RECOVERED BY COLLECTING IT IN A SOLID, SUB-DIVIDED MASS, E.G., COKE OR CATALYST, AS IN A FLUIDIZED BED AND THEN CONVERTED IN A CONVERSION ZONE. IN A SPECIFIC EMBODIMENT, COOLED VAPORS FROM AN OIL SHALE RETORTING ZONE ARE TREATED TO SEPARATE LIQUID OIL AND AN OIL MIST THEREFROM, THE OIL MIST IS ABSORBED ON A SOLID, SUBDIVIDED   MASS AND THE MASS CONTAINING THE ABSORBED MIST IS PASSED TO A CONVERSION ZONE.

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Feb. 2, 1.971

INVENTOR. H. W. PARKER M '01 1 v A T TORNEVS United States Patent 3,560,367 RECOVERY AND CONVERSION OF SHALE OIL MIST Harry W. Parker, Bartlesville, Okla., assignor to Phillips Petroleum Company, a corporation of Delaware Filed Oct. 13, 1966, Ser. No. 586,533 Int. Cl. ClOg 1/00 U.S. Cl. 208-11 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to the recovery of a shale oil mist. It also relates to the conversion of a shale oil mist. In one of its aspects, the invention relates to an operation in which crushed oil bearing hydrocarbonaceous solid such as oil shale is retorted producing liquid shale oil and a shale oil mist, and the shale oil mist is recovered. In another of its aspects, the recovered shale oil mist is converted as by pyrolysis.

In one of its concepts, the invention provides a method for recovering shale oil mist by collecting same in a solid subdivided mass, e.g., dry coke, catalyst, etc. In another of its concepts, the invention provides such a method in which the shale oil mist is recovered in a fluidized bed of such a mass. In a further concept, the invention provides a method in which when coke is used the coke is produced in a coking operation. In a still further concept of the invention, coke from a coking operation is cycled to a mist collecting zone wherein the shale oil mist is collected onto the coke, and the coke is then recycled to the coking zone. A further concept of the invention involves employing a gas derived from the overall coking operation to aid in the separation and beneficiation of the shale oil and oil mist in the shale retorting operation. In a further concept of the invention, some or all of the mist containing retort product is directly adsorbed in a solid and then further treated.

It is now well known that there exists in this country and elsewhere large deposits of oil shale. The recovery of the oil from the oil shale presents a number of problems. These problems ars also well known. Among the problems involved usually are the corrosive character of vapors evolved from the oil shale, the expense of retorting the oil shale as viewed from a physical handling of the same viewpoint, and recovery of the gaseous and vaporous products thus produced. Among the problems of recovery, there is the problem of suitably recovering so-called oil mist emanating from the retorting operation.

It has now occurred to me that the oil mist can be quite efliciently recovered by contacting the same under suitable conditions with solid particles of coke or catalyst, e.g., a pyrolysis catalyst, for example a silica-alumina catalyst. Further, it has occurred to me that the solid can be maintained in a fluidized bed. Still further, I have conceived that the coke or catalyst can and preferably should result from a coking or cracking operation so that as desired the coke or catalyst containing oil mist can be cycled back to the operation for immediate recovery of valuable products existing in or produced from said mist. Still further, it has occurred to me that by making the combination described herein, I will have available Patented Feb. 2, 1971 a gas stream which suitably can be beneficially employed to aid in the retorting operation and in the recovery of oil and oil mist from the crushed shale being retorted.

The operation of the several concepts of this invention severally and more particularly as these may be combined, as described herein, results in very considerable savings in plant investment and also in the production of a superior product at a lower cost. Thus, I believe that I have materially contributed to the overall problem of rendering the recovery of oil from oil shale more nearly competitive, if not competitive, with oil produced by currently commercial operations.

It is an object of this invention to recover an oil mist obtained from oil shale. It is another object of this invention to convert an oil mist recovered from an oil shale. It is a still further object of this invention to provide a method for so collecting oil mist derived from retorting of oil shale that the oil mist can be immediately further processed for its ultimate recovery and/or its conversion. Still further, it is an object of this invention to provide a combination of operations resulting not only in the efficient recovery of oil mist derived from retorting of oil shale, but also permitting its conversion to useful products. It is still further an object of this invention to provide a method of steps in combination resulting in the recovery and conversion of oil mist derived from retorting of oil shale in which method there can be obtained from the overall operation a stream which will aid the initial retorting of the oil shale.

Other concepts, objects, and the several advantages of this invention are apparent from a study of this disclosure, the drawing and the appended claims.

According to the present invention, there is provided a method for the recovery of oil mist derived from the retorting of oil shale which comprises adsorbing the oil mist on particles. In one form of this concept of the invention, the oil mist is recovered on fluidized coke particles. The use of a cracking or pyrolysis catalyst in a. cracking operation in which the mist adsorbed on the catalyst is passed to the cracking zone is also contemplated.

Also according to the present invention, there is provided a combination operation in which the solid is derived from an operation to which the solid containing the recovered oil mist can be cycled. In the preferred form of this concept of the invention, the solid is also in fluidized condition and the coking or cracking is conducted in a fluidized coking or cracking operation.

Still according to the present invention, there is provided a method wherein gaseous products separated from the operation is employed to aid in the more effieient recovery of vaporous and gaseous products from the oil shale being retorted.

The present invention is particularly and most advantageously embodied in an operation in which a fluidized coking operation is effected and in which a fluidized coke bed is used to absorb the oil mist. One skilled in the art in possession of this disclosure having studied same will recognize that the coke need not be fluidized, in the sense that the coke particles and vapors can be treated as a fluid, but can be in the form of a moving bed, for example, a downwardly moving bed of particles which are in contact each with the other.

A patent which illustrates the use of downwardly flowing solid heat exchange material for the ultimate heating of oil shale when it is mixed with said material and in which the solid heat exchange material can be stripped shale or a mixture of stripped shale and a refractory heat exchange pebble is US. Pat. No. 2,726,978, issued Dec. 13, 1955, Robert A. Findlay.

In the drawing there is shown diagrammatically an embodiment of an operation according to the invention in which the several concepts thereof have been combined in a unitary arrangement in which, further, according to the invention, the shale oil mist which is recovered by coating the same onto coke is recovered on coke which has been derived from the liquid portion of the shale oil derived from the retorting of the shale.

Viewing the drawing, one skilled in the art in possession of this disclosure having studied the same will comprehend that certain ancillary operations or steps have been omitted for sake of simplicity. He will also know what are generally the conditions for retorting shale, operating a mist collector, coking an oil, conveying coke particles and cooling the same.

Referring now to the drawing, crushed shale is fed at 1 into retort 2 from which spent or retorted shale is removed at 3. To create the heat necessary to pyrolyze or to decompose the kerogen, air is passed by 4 into retort 2. Retort 2 can be otherwise heated as known in the art. In the retort, the kerogen will begin to decompose at a temperature in the approximate range of 440-660 F. A substantial amount, if not substantially all of the oil or oily materials formed from the decomposition of the kerogen will have been removed from the shale at a temperature within the approximate range of 840-1020 F. Vaporous products are taken overhead from retort 2 by 5 and passed by coolers 6 and 7 to cyclone mist separator 8. Continuous type crushed shale retort operation is shown. The temperature in this operation can be varied as indicated, but in any event, the cooler 6 is operated to cool the vaporous products to a temperature in the neighborhood of approximately 100 F., and accordingly, the interior of the cyclone 8 will be at a temperature of approximately 98 F. in the embodiment being described. Approximately three percent of the oil will leave the cyclone as a fine mist by 9, the remainder or bottoms liquid are passed by 10A to fluid coker 11 in which the fluid coking operation is conducted according to known manner and conditions. The oil from 10A is admixed with hot coke in 11 and as a result of the coking operation there are produced a stream of oil vapor coking products taken overhead by 12 to oil recovery, and coke removed at 13 and passed into coke cooler 14, thence to fluid bed mist collector 15 by 14A, wherein oil mist from 9 is adsorbed upon the cool coke. A blower 9A moves the gas through the retorting, mist collecting and coke cooling sections. The cool coke containing the oil mist is passed by 16 into fluid coker 11. There is contained in the oil mist considerable gas and this shale gas is passed by 17 into counter flow with the coke in cooler 14, cooling the coke while itself is heated and then recycled by 10 to retort 2. Excess shale gas is vented at 17A. Retorted shale is passed by 3 to shale burner 18 from which spent shale is removed at 19. Hot gases from 18 are passed by 20 to coke heater 21 into which coke from fluid coker 11 is passed by 13A. Excess coke is removed at 13B. Hot coke for the coking operation in 11 is passed from 21 by 22.

The products from fluid coker 11 removed therefrom by 12 and treated in conventional manner as now known in the art. As will be understood by one skilled in the art, there can be introduced air into coke heater 21 which will supplement residual air or oxygen which may be contained in the gases transmitted by 20.

It will be evident to those skilled in the art in possession of this disclosure, having studied the same, that the foregoing diagram and its description are simply put to set forth the inventive concepts. Thus, it is evident that engineering details, apparatus parts, etc., will and can be supplied employing routine skill in the art.

A consideration of the foregoing diagram as it has been described will show that in a unitary operation several concepts of the invention have been combined in its more specific concept to, in one overall operation, retort crushed shale to form liquid shale oil and shale oil mist, the oil mist bile been recovered by adsorption on coke,

4 and coke in a coking process, which not only generates the coke but which also cokes the liquid shale oil.

The present invention, especially in its now preferred and overall combination embodiment permits effecting certain economies which bring the commercial processing of oil shale considerably closer to an in being situation or reality. It has been estimated that mining, oil mist recovery, and hydrogenation together account for about 63 percent of the oil value. This indicates that a major breakthrough in at least two of these areas will be necessary to substantially lower the high indicated value of refinery feed derived from oil shale.

Viewed from a plant investment viewpoint in which mining and crushing, screening and conveying, retorting, oil mist recovery, delayed coking, and water, steam and power units costs have been included, oil mist recovery, absent the present invention, has been estimated at over 28 percent. Therefore, any operation which permits effective beneficiation of the oil shale to recover the shale oil and the shale oil mist can be considered to be a very desirable step in the right direction, namely, the direction of commercial beneficiation of oil shale.

The following tabulation is of conditions, etc., given by way of specific example of an operation in which 50,000 barrels per day of oil is produced.

SPECIFIC EXAMPLE Temperatures, F.

Retort 2 (maximum) 1200 Pipe 5 125 Pipe 7 Cyclone 8 98 Pipe 10 "a 995 Pipe 14A Pipe 17 100 Fluid coker 11 1000 Pipe 20 1200 Pressures P.s.i.a.

Retort 2 12 Pipe 5 11.5 Fluid coker 11 14 Fluid bed mist collector 16 Coke cooler 14 Flow rates Crushed shale, tons per day 80,000 Recycle gas, pipe 10, cubic feet per minute 4,400 Gas containing oil mist, pipe 9, c.f.m. 4,400

Vapors from coking operation on liquid basis,

pipe 12, barrels per day 50,000

Whereas herein the use of coke and a coking operation have 'been described in some detail, the application of the invention to a cracking or other catalytic operation is also contemplated, the invention being directed to a combination operation.

While one skilled in the art in possession of this disclosure, having studied the same, will select operational factors which he deems optimum, the particle size of the coke employed should be preferably in the range of approximately 48 to 100 mesh. Under such conditions, adsorption of oil upon the coke will be in the neighborhood of about 10' percent by weight.

It is within the scope of the broad concept of this invention to directly pass a part or all of the oil mist directly to the operation in which the solid subdivided mass is undergoing treatment or is being utilized. Under such circumstances, non-condensibles produced in the retorting operation and present in the mist will pass through the operation to which the mist is fed and will be recovered at least in part as at least a portion of the residue gases of that operation.

It will be evident to one skilled in the art having studied this disclosure that depending upon the source of the oil shale or other oil-bearing material or solid that the retorting conditions, oil mist adsorption conditions, and coking conditions as these may be used will vary. The

invention as expressed herein is found in the several concepts which have been stated and which are evident from a study of the disclosure. The invention of the claims is to be limited only in the sense of the methods there described and delineated.

Reasonable variation and modification are possible within the scope of the foregoing disclosure, drawing and the appended claims to the invention, the essence of which is that there has been set forth a method for the recovery of shale oil mist by adsorbing the same on a solid subdivided mass, for example, coke, a cracking catalyst, etc., for example on a fluidized bed of coke or catalyst or contact mass, in one embodiment of the invention further comprising operating a process from which the coke, catalyst or contact mass for the mist adsorption is derived and to which the mass with the adsorbed mist can be passed, the invention further comprising in one of its more detailed concepts as principal feed for said process the liquid shale oil obtained from retorting of crushed shale, the overall process being further modified in that gases obtained during the process and/or retorting are recycled for use to aid in the retorting as well as in the fiuidization of the bed in which the mist is adsorbed when said bed is in fact fluidized.

I claim:

1. A method of beneficiating an oil bearing hydrocar' bonaceous solid such as oil shale to recover therefrom shale oil and related products which comprises retorting said oil shale producing in a shale retorting zone shale oil vapors containing a condensable portion, cooling said vapors to condense a condensable portion thereof, separating, from the condensed portion thus obtained, a liquid portion as a liquid stream, obtaining a vaporous stream containing shale oil mist consisting of liquid mist particles, recovering said shale oil mist by adsorbing said liquid mist particles upon a solid subdivided mass of coke or a cracking catalyst and then in another zone further treating said mass containing said oil mist particles to produce oil conversion products therefrom.

2. A method according to claim 1 wherein the mass is in the form of a bed of coke particles.

3. A method according to claim 1 wherein the mass is a catalyst bed.

4. A method according to claim 2 wherein the coke is derived from a coking operation.

5. A method according to claim 4 wherein the coking operation feed is shale oil derived from retorting oil shale.

6. A method according to claim 5 wherein the coke containing the adsorbed mist is passed into the coking operation for coking treatment therein.

7. A method according to claim 6 wherein coke from the coking operation is cooled and then used to adsorb said mist.

References Cited UNITED STATES PATENTS 1,570,205 1/ 1926 Collier et al. 20811 2,694,035 11/1954 Smith et al. 208-126 2,726,999 12/1955 Brandt et al. 203--7 2,982,701 5/1961 Scott 201--27 3,058,903 10/1962 Otis 208-126 2,635,709 4/1953 Archibald et al. 5574 2,901,402 8/1959 Putnam 208--11 3,252,270 10/1962 Pall et al. 5574 2,694,037 4/1950 Johnson et al. 20811 3,164,541 8/1960 Linden et al. 208-11 3,259,565 3/1963 Kimberlin 208127 3,281,349 7/1963 Evans 20811 35 HERBERT LEVINE, Primary Examiner US. Cl. X.R. 20810l, 103 

